Two slits are kept 1 mm apart and the screen is placed 1.0 m away. What is the fringe separation when blue-green light of wavelength 500 nm is used?

0.05 mm 0.5 mm 5.0 mm 50.0 mm

0.5 mm

Fringe Width is $\beta = \frac{\lambda D}{d} = \frac{500\times 10^{-9}\times 1}{10^{-3}} = 500\times 10^{-6} =0.5 mm$